How much water evaporation should I expect? Or is my tank leaking somewhere?

[Andrew Schubert]

I was wondering how much water evaporation I should expect from my tank in a day. I just measured it and my sump was down .75 gallons in a day. Is this normal? I have a 120 gallon acrylic tank with a 30 gallon sump. My water temperature has been right around 78 degrees.

I have noticed a 'little' water underneath the front lip of my tank, which I think has just gotten trapped there from it running down my arms and front of the tank during water changes and such. It doesn't seem to be getting any worse. Nothing trickling down the stand or getting on the floor. But I sure would love if someone could verify that 3/4 gallon of evaporation a day seems normal for a tank this size?

 

[Crabs McJones]

Depended on your climate, that is perfectly normal, my 40 breeder goes through about 5 gallons of ato a week

 

[PDR]

I would say that’s pretty normal. My 50 gallon frag tank evaporates 1.5 gallons a day.

 

[CMO]

I get about 1.75g per day on my ~200 total system volume so seems like you're doing much better than I! Tank is set to 78 with house thermostat at 74.

 

[saltyhog]

Agree, pretty normal. My 155 gallon tank/45 gallon sump has a 16 gallon ATO reservoir. It lasts about 10 days in the summer and about 7-8 in the winter when the indoor humidity is lower.

 

[Idoc]

My 75g tank plus 25g in the sump typically evaporates about 1-1.5g per day.

 

[maroun.c]

It can very much vary based on ambient humidity levels. The dryer it is the more evaporation to expect.

 

[JumboShrimp]

Lots of surface area on my 6’ tank, lots of surface area on my sumps, waterfall type algae scrubber... it all ads up to about 2 gallons a day evaporation.

 

[DesertReefT4r]

If you SG gets low you may have a leak, ATO keep adding RODI and saltwater is leaking out. Your evap rate is pretty normal. I live in Phoenix Az and its very hot and dry. My 75g with 20g sump about 65g total system volume evaps 5g a week.

 

[Andrew Schubert]

Thanks for all the replies. My tank is located in the basement, and at the moment humidity is at 55%. I never took the time to measure the amount of evaporation until now. It just seemed like lately the water was evaporating faster than usual. I just installed an emperor aquatics uv sterilizer that had a small leak I had to patch up. It was an open-box item from bulk reef supply. * Side note: there customer service is amazing. They took 50% off the item, and all it needed was a little silicone to seal it back up. So I ended up getting a $390 unit for just over $125 (can't beat that!). Anyways, I was afraid something I added was causing a leak I couldn't find! Guess the most logical reason is the change to the fall season. During the summer I ran a dehumidifier in the basement, and the humidity was still no lower than 60% most of the time. Guess I'll probably seem even higher evaporation as the winter continues to roll around. Thanks!